WO2009003929A1

WO2009003929A1 - Method for separating carbon dioxide from flue gases and associated device

Info

Publication number: WO2009003929A1
Application number: PCT/EP2008/058240
Authority: WO
Inventors: Thomas Hammer; Werner Hartmann
Original assignee: Siemens Aktiengesellschaft
Priority date: 2007-06-29
Filing date: 2008-06-27
Publication date: 2009-01-08
Also published as: US20100196234A1; CN101790409A; DE102007030069A1; RU2473379C2; EP2164613A1; RU2010102885A

Abstract

Adsorption methods for separating carbon dioxide (CO2) from flue gases are known. According to the invention, the CO2 is placed on an adsorber and an adsorption reaction with ammonia, that is used as a chemical absorption agent, takes place. The CO2 extracted from the waste gas is joined to the ammonia on the catalytic surface thereof by means of a heterogeneous, catalytic reaction. At least two reactors (10, 10', 20, 20'; 30, 30') are provided in the associated device, said reactors, which operate alternately, being switched between the adsorption of CO2 and the regeneration of the absorption agent.

Description

description

Process for the separation of carbon dioxide from flue gases and associated apparatus

The invention relates to a process for the separation of carbon dioxide (CO ₂ ) from flue gases using an adsorption process in which the CO _{2 is} attached to an adsorber. In addition, the invention relates to an associated apparatus for carrying out the method.

Reducing the emission of the greenhouse gas carbon dioxide (CO ₂ ) from power plants and industrial plants can be achieved by using low-carbon fuels.

However, the latter is not an option for existing plants designed to use high-carbon fuels, such as lignite-fired power plants in particular. Here separation processes are required, the CO ₂ z. B. from the flue gas or the exhaust gas.

When flue gases all arising during the combustion process gases are referred to, wherein below consistently exhaust ge ^¬ is addressed.

The removal of CO ₂ from exhaust gas can be done by physical or / or chemical binding in the volume ("absorption") or by attachment to active surfaces ("adsorption").

The physical or chemical absorption is in both cases multi-step processes, in which the CO ₂ -containing exhaust gas is brought into contact with a physical or chemical absorber until it is completely loaded with CO ₂ . Thereafter, the absorber must be discharged, the CO _{2 is released} in the presence of a Spulgases and finally separated from this. Potential problems here are the slippage necessary for the Bin ^¬ dung substance, ie, the absorber, the doors ^¬ voltage of the CO ₂ from the Spulgas in a form which allows further use of the CO _2, and possibly the high energy consumption for regeneration especially in the case of chemical bonding.

Recently the binding of CO ₂ has been proposed by means of ammonia, a method which has long been known from the ammonia synthesis (see Parrish, Roger Warren: "Process for manufacture of ammonia", EP 0247 220 Bl and in zi ^¬ formatted font Uhde, Georg Friedrich: "Method of separating ammonia from gases and mixtures of gases containing ammonia", US 1 745 730 A), wherein in the case of the separation of CO ₂ from exhaust gas ammonia slip can occur and also the separation of CO ₂ and NH ₃ , which is bound as ammonium carbonate or ammonium bicarbonate, causes problems.

Alternatively, it is possible to work with adsorbers to which the CO ₂ in a first process step z. B. is stored at low temperature or high pressure and desorbed in a second process step at high temperature or low pressure (so-called "pressure swing adsorption" or "temperate swmg adsorption"). There is an efficiency problem here because the Adsorptionskapazitat is significantly smaller than the capacity of absorbers, with a high energy demand arises in order to pass through temperature and pressure cycles can.

DE 1 911 670 A describes a process for the purification of gases which contain acidic components such as CO ₂ , in which case as in the following three documents the further use of the purified gas is the primary objective and not the further use of the adsorbent bound gas. JP 04-022415 discloses the separation of CO ₂ from process gases for the semiconductor industry by means of adsorption on ammonia-laden zeolites, the CO ₂ being chemically chemically oxidized by reaction with the ammonia at ambient temperature remains bound. The separation of CO2 from exhaust gases, z. B. of thermal power plants, by carbonate formation at Tempe ^¬ temperatures between 600 ⁰ C to 800 ⁰ C, is disclosed in JP 10-272336 A. Finally, in the publication "Applied Surface Science", Vol. 1-4, p. 235-242 (2004) demonstrated that a Praparation of activated charcoal by means of leads ^¬ Am monia for improved binding of CO _2. In neither case, a method is disclosed, with the conditions the removed from the gas to be purified CO2 for further use or disposal with reasonable energy costs who can ^¬.

In addition, membrane processes for the separation of CO _{2 are} possible, but hitherto, for cost and efficiency reasons, ie, low selectivity of the separation process between CO ₂ and, for example, N ₂ , are unsuitable for applications in large plants.

On this basis, it is an object of the invention to propose an improved process for the large-scale emission reduction of carbon dioxide (CO ₂ ) and to provide an associated device. In this case, the CO2 from the exhaust gases is to be separated so that the subsequent use for landfilling the CO _{2 is} possible.

The object is achieved with respect to the method by the measures of claim 1, wherein the invention results as a sequence of individual process steps. An associated device is the subject of claim 19. Further developments of the method and the associated device will become apparent from the respective dependent claims.

According to the invention, it is proposed to carry out the binding of CO ₂ from waste gas in an adsorption reactor by means of a heterogeneous catalytic reaction with ammonia as chemical absorber, which is bound to the catalytic surface. The process is carried out at low temperature T, so that the carbon-containing reaction products, such as B. Isocyanic acid (HNCO) and urea ((NH ₂ ) ₂ CO), are bonded to the catalytic surface according to the following reaction equations, wherein the bound to the catalytic surface molecules are marked with an "s":

NH ₃ (S) + CO ₂ -O- HNCO (s) + H ₂ O (1)

HNCO (s) + NH ₃ (S) <r ^ (NH ₂ J ₂ CO (S) (2)

A suitable temperature range is dependent on the catalyst used, especially at temperatures below T = 200 ⁰ C, and advantageously amounts to in the present invention:

70 ⁰ C <T <140 ⁰ C (Ia)

The equilibrium of reaction (2) is at low temperatures and high surface concentrations of NH ₃ on the right side of the reaction equation, but at high temperatures or low surface concentrations of NH ₃ on the left side.

Subsequently, the catalyst is regenerated, excluding the Abga ^¬ ses at a higher temperature in a gas mixture of ^¬ serdampf and CO ₂ , wherein CO _{2 is} selectively released and thus fed to a final separation, but the absorbent is returned to its original state and thereby remains bound to the surface:

HNCO (s) + H ₂ O → NH ₃ (s) + CO ₂ (3)

Reaction (3) represents the inverse of Reaction (1), which is forced by providing excess water vapor and raising the temperature above the window indicated in (Ia). This shifts the equilibrium of the reaction (2) to the left side because isocyanuric acid (HNCO) is constantly eliminated by the hydrolysis reaction (3). The subsequent separation of water vapor and CO ₂ can be achieved by condensation by means of suitable pressure and temperature control.

Alternative reaction mechanisms, the z. B. lead to the formation of ammonium carbamate NH ₂ CO ₂ NH ₄ ⁺ , are also representable when choosing suitable reaction parameters (low temperature) and catalysts:

2 NH ₃ (S) + CO ₂ → NH ₂ CO ₂ ^~ NH 4 ⁺ (s) (4)

Ammonium carbamate (NH ₂ CO ₂ ^~ NH ₄ ⁺ ) can be converted to ammonium carbonate by hydrolysis in aqueous solution or on a suitable catalytic surface even at low temperatures:

NH ₂ CO ₂ ^" NH ₄ ⁺ (s) + H ₂ O → (NH ₄ ) ₂ CO ₃ (5)

The ammonium carbonate decomposes thermally with an increase in temperature, with elimination of water in NH ₃ and CO ₂ :

(NH ₄ ) ₂ CO ₃ → 2 NH ₃ (S) + CO ₂ + H ₂ O (6)

Suitable catalysts can be used to ensure that NH ₃ remains bound to the surface. The subsequent separation of water vapor and CO ₂ can be achieved again by condensation by means of suitable pressure and temperature control.

In the device according to the invention at least two reactors are present. In this case, it is possible to implement as different arrangements for the current-technical implementation of the above-described inventive method: - Two parallel reactors are alternately charged to adsorb the CO ₂ with exhaust gas and the respective Arbeitsreak ^¬ tor when the adsorber is largely implemented, taken from the exhaust stream and fed with the brought to the required temperature regeneration gas.

- Depending on an adsorption reactor and a regeneration reactor lie ^¬ gen parallel to each other so that the catalyst tion required for the Reaktionsfuh-, by a gas lock from the adsorption to the regeneration reactor and be guided back.

For the latter, it makes sense to design the catalyst, for example, as a rotatable disc stack, which is arranged so that the catalytic surfaces alternately pass through the adsorption and the regeneration reactor.

Alternatively, the flow of catalyst particles in countercurrent is possible.

The advantages of the above-mentioned invention over the previous methods, which work with liquids such as ammonia in aqueous solution, are essentially that by selecting suitable catalysts with binding sites for NH _3, the ammonia slip can be greatly reduced. In addition, the reaction kinetics can thereby be made much more selective, so that the formation of undesirable by-products is suppressed, which consume the absorber or lead to an energetically strong only with high energy expenditure releasable binding of CO ₂ .

Furthermore, it is advantageous that a substantial part of the CO _{2 is separated} from exhaust gases in such a form, which allows the subsequent use of CO ₂ with little energy consumption in order to come to a sustainable CC ^ -Emissionsminderung. As catalytic materials preferably oxides and Mi ^¬ mixtures of oxides come into consideration such. B. T1O ₂ and V ₂ Os, with titanium dioxide z. B. is a suitable hydrolysis catalyst, while V ₂ O _{5 is} favorable for the binding of ammonia to the O- berflache. Alternatively, ion-exchanged zeolites can be used as catalysts, which can also bind ammonia very selectively.

The application of the inventive method is msbeson- particular interest in the CO ₂ separation ammonia solutions at process temperatures> 10 ⁰ C, since in this case is still present a abhangiger on the temperature ratio of NH ₃ in the range of several percent by volume in the separated CO _2, which can not be economically eliminated by conventional methods.

Further details and advantages of the invention will become apparent from the following description of exemplary embodiments play with reference to the drawing in conjunction with the patent entitlements.

Each show in a schematic representation

1 shows an arrangement for the CO ₂ separation of exhaust gas with the aid of a solid catalyst and

2 shows an alternative to Figure 1 arrangement with a rotatably mounted plate catalyst,

3 shows a further arrangement with catalyst particles, and FIGS. 4 and 5 show the sensoπk in the case of an alternating function of the reactors according to FIGS. 1 to 3 as adsorption reactor on the one hand or as desorption reactor on the other hand.

Subsequently, the two figures are individually be ^¬ wrote. Here, the essential elements such as the reactors and valves including the lines which have the same function, the same reference numerals. In Figures 1 to 3 are respectively two identical Reacto ^¬ ren 10 or 10 ', 20 and 20' and 30 or 30 'are present, which are operated in alternating operation. For example, for

FIG. 1, while one of the two reactors 10, 10 'serves to adsorb the CO ₂ in the CO ₂ -containing exhaust gas, the other of the two reactors 10, 10' is discharged, which will be explained in detail below. For such alternating operation fluid lines with a number of Venti ^¬ len are necessary as well as a Vorratsbehalter for an absorbent for CO ₂ and a unit for separating the CO ₂ from Regenerat.

The two reactors 10 and 10 'of Figure 1 each have a catalyst bed 11 and 11' on. Cθ ₂ -containing exhaust gas is supplied via an exhaust pipe 1 and guided via the branch 2 either into the first reactor 10 or via a parallel line 1a with a branch line 2a into the second reactor 10 'connected in parallel. For this purpose, valves V1, V2, V7 and V8 are connected in the lines 1, Ia. The associated control unit is not shown.

Each one of the reactors 10, 10 'is thus in the adsorption onsbetπeb, while the other reactor is in regeneration mode. For this purpose, from the other side of the reactors, a reaction gas mixture, which is also referred to as regenerate, fed via the line 6 with the parallel line 6a and the branch lines 7 and 7a the two reactors in the alternating operation. For m are the lines 6, 6a valves V3, V4, V5 and V6 connected, the function of which results from the representation of the alternating operation. Via the line 8 Cθ ₂ -reduced exhaust gas is led away and guided via the line 3 Cθ ₂ -containing regenerate to the unit 5. In the unit 5, the CO ₂ separation is carried out by the regenerate, so that here Rei ^¬ nes CO ₂ dislocation is carried away. The container for the absorbent is denoted by 4 and via a valve V9 with the fluid circuit in operative connection. The two reactors 10, 10 'in Figure 1 have - as already mentioned - catalyst beds 11 and 11' containing a solid catalyst, the z. B. is formed as a plate catalyst. Alternatively, such a catalyst bed can also be designed as a so-called packed bed.

Figure 2 shows a simplified representation of an alternative arrangement to Figure 1 with reactors 20 and 20 '. The individual valves are not shown here except valve V9. The two reactors 20, 20 'are connected to each other via a gas-tight lock. Instead of the catalyst beds from FIG. 1, plate catalysts 15 arranged rotatably about a vertical axis are present here. Both reactors are connected via a gas-tight lock 30, wherein a fully loaded catalyst half can be brought into the second reactor by rotation for generation by rotation of the catalyst plate assembly and the discharged catalyst plate half is available for reloading. Otherwise, the alternating principle with the supply of a regeneration gas mixture ("regenerate") on the one hand and separation (CO2) on the other hand from the exhaust gas is identical It is essential in both cases that absorbers can be added to the regenerator in a controlled manner after the CO ₂ separation to compensate in practice for unavoidable loss of regeneration agent.

Other embodiments of the invention include plate reactors coated with catalysts, in particular those with moving plates or other structures having a large specific surface, in which the plates are circulated in a discharge manner from the loading area (flue gas, CO ₂ gas stream) via a lock system into the discharge area CÜ ₂ separation and back to the loading area. In contrast to FIGS. 1 and 2, the invention defined by the protective claim also includes arrangements in which the gas stream to be purified is passed through a fluidised bed reactor, whereby in particular small particles and those with a high specific surface, The loaded particles are continuously removed from the loading area, fed to a desorption area and then recirculated back into the adsorption reactor.

In a simplified arrangement according to FIG. 3, in a further arrangement, the gas stream to be purified is passed through a "shower" of catalyst-coated particles with a high specific surface in a countercurrent process ("trickle reactor"), the loaded particles likewise being taken off continuously, regenerated and discharged Rieselreaktor be fed back.

In FIG. 3, two reactors 30 and 30 'are shown, which operate in countercurrent flow. Both reactors 30, 30 'have catalyst plates 31 and 31', which are each designed as a bed of catalytic particles. Both reactors 30 and 30 'are connected at their ends by a gas-tight lock 32 and 32', respectively.

Otherwise, the device operates according to Figure 3 according to Figure 2. It is essential here, however, that the CO ₂ -containing exhaust gas is introduced via line 1 into the reactor 30 and flows there in countercurrent to the catalyst particles. Correspondingly, conversely, the regenerate is introduced into the reactor 30 ', in which case the catalyst particles in turn flow in countercurrent according to the arrow. In practice, a flow pump is used for this purpose, which is not shown in detail in FIG.

The Sensoπk one hand, and the signal processing are not included in the examples of Figures 1 to 3. In the way It is similar for all three examples according to FIGS. 1 to 3 and is explained in detail with reference to FIGS. 4 and 5.

In FIG. 4, an adsorption reactor is referred to as 40. For the flue gas supply via a line 41 is a valve VlO and for the gas discharge at the outlet of the reactor via the line 49, a valve VIl is present. In the adsorption reactor 40, a temperature sensor 42 and a gas sensor 43 for the CO ₂ concentration are located on the input side. Another gas sensor 44 for the CO ₂ concentration is present on the downstream side. It is therefore essential that the concentrations c (CO ₂ ) at the input on the one hand and on the output on the other hand can be measured and correlated with the temperature T according to a thermally activated process. From the decrease of the CO ₂ concentration at a certain temperature T, the adsorption capacity of the adsorber can be determined. When the adsorption capacity falls below a certain limit, regeneration is initiated.

In the figure 5 a desorption reactor 50 is shown, the input lines 51, 51a and an output line 59 has ^¬. Again, there are valves V12 and V13 in the inlet and outlet, and further in the supply line 51a, there is a valve V14 for the supply of an absorbent.

In the desorption reactor 50, a sensor 52 for the temperature T and at the output a sensor 53 for the concentration c (Abs) of the absorbent is present at the entrance. The signals for the concentrations on the one hand and the temperatures on the other hand are processed in a control device not described in detail, for example a known microprocessor control unit. Essential criterion for the

Control is that the adsorption capacity of the catalytic material for CO ₂ , which is determined from current CO ₂ measurements on the adsorption reactor, by storing Absorbent on the catalytic surface in rea ^¬ chender manner is maintained. For this, valve V12 is closed to stop the supply of Desorbergasgemisch. Then, valve V14 is opened to supply absorbent (eg, ammonia). Shortly afterwards valve V13 is closed to a slip of the Absorptionsmitteis to vermei ^¬. As soon as the sensor 53 in the outlet region of the desorption reactor 50 detects absorbent concentrations above a first limit value, valve V14 is closed.

During proper operation of the device temperature T and absorbent concentration c (Abs) are monitored by sensors: With decreasing temperature T increases in an intact catalyst, the storage capacity for the sorbent, so that the concentration c (Abs) of the still in the gas phase Absorptionsmitteis after short waiting time falls below a classified as safe, second threshold and the reactor or the laden with Absorptionsmit ^¬ tel catalyst can be put back into operation. Deviations from this behavior give evidence of damage to the catalyst either by mechanical, thermal or chemical influences, where appropriate ^¬ if a maintenance of the system can be made.

The devices with two reactors described with reference to the figures can advantageously be used for the separation of CO ₂ from CO ₂ -containing exhaust gases. In particular, the following process steps take place:

- The CO ₂ -containing exhaust gas is passed through a catalyst, is attached to the active centers NH ₃ .

At a first process temperature, the CO _{2 is} converted by means of ^chemical reactions with the NH ₃ into a stable compound likewise bound to the catalyst surface. This temperature is designated T _x . - The so loaded with CO2 catalyst is at a second process temperature, which is higher than the first process temperature, a Coulomb, consisting of CO ₂ and water vapor (H ₂ O) exposed. This temperature is measured with T ₂ draws (T ₂ > T _x ). At this temperature, the compound decomposes from CO ₂ and NH ₃ , the CO ₂ is released into the Spulgasstrom, while the NH ₃ remains attached to the surface of the catalyst. - The enriched with CO ₂ Spulgasstrom is überfuhrt in the other reactor and there to a temperature which is niedri ^¬ ger than the first process temperature, cooled. This temperature is T ₃ denotes (T ₃ <Ti). At this temperature, the water is condensed and discharged.

Through this Temperaturfuhrung the pure, dry CO _{2 can} then be pumped off the water surface and fed to another use.

Overall, it can be stated that the separation of CO _2, in particular from flue gases and, in principle, from CO ₂ -containing exhaust gases of all kinds takes place in a manner with the method described above and with the devices created for its implementation. This makes it possible to reduce the CO ₂ emission of climate-damaging greenhouse gases. It is essential that the CO _{2 is present} at the end of the specified process in almost pure form, so it z. B. for storage in natural gas or oil fields at the same time ^¬ increase in the Fordermenge (so-called. "Enhanced oil recovery", "enhanced gas recovery") can be compressed. Of secondary importance, however, is the completeness of the separation of the CO ₂ from the flue gas: A remainder of 10% of the original CO ₂ content can easily remain in the flue gas, if characterized z. B. the energy cost of the separation can be kept small against the energy conversion of the plant that emits the flue gas.

In the system, an oxidic catalyst is advantageously used as adsorber. The catalyst consists for example of titanium oxide (TiO ₂ ) or a mixture of

Titanium oxide (TiO ₂ ) and with another metal oxide, in particular doped with vanadium oxide (V ₂ O ₅ ). He can also be one ion-exchanged zeolites exist.

The desired goal of being able to represent carbon dioxide (CO ₂ ) at the end of the process according to the invention in pure form for further use or disposal can now be achieved in an efficient manner.

Claims

claims

1. A process for the separation of carbon dioxide (CO ₂ ) from exhaust gases by heterogeneous catalytic reactions of carbon dioxide (CO ₂ ) with ammonia (NH 3), with the sequence of the following process steps:

The CO ₂ -containing exhaust gas is passed over a catalyst to whose active centers NH _{3 is} attached,

- In this case, the CO _{2 is transferred} at a first process temperature (Ti) by chemical reactions with the NH 3 in a stable, e- benfalls bound to the catalyst surface compound,

- Subsequently, the thus loaded with CO ₂ catalyst at a second process temperature, which is higher than the first process temperature (T ₂ > Ti), a Spulgasstrom, consisting of CO ₂ and water vapor (H ₂ O), exposed decomposes the compound of CO ₂ and NH ₃ , the CO _{2 is} discharged into the Spulgasstrom, but NH ₃ remains attached to the surface of the catalyst, - then the enriched with CO ₂ Spulgasstrom is transferred into another reactor and there to a temperature , which is lower than the first process temperature (T ₃ <Ti), cooled, the water is condensed and discharged from ^¬ , finally the pure, dry CO _{2 is} pumped off over the water surface and fed to a further use.

2. The method according to claim 1, characterized in that the first process temperature at temperatures below

200 ⁰ C is selected so that carbonaceous Reacti ^¬ onsprodukte, such as isocyanic acid (HNCO) and urea ((NH ₂ ) ₂ CO) are bound to the catalytic surface.

3. The method according to claim 1 and claim 2, characterized in that the first process temperature in the range of 70 ⁰ C to 140 ⁰ C.

4. The method according to claim 2 or claim 3, characterized in that the binding to the catalytic surface GE measure the following reaction equations takes place

NH ₃ (S) + CO ₂ O HNCO (s) + H ₂ O (1)

HNCO (s) + NH ₃ (S) <r ^ (NHz) ₂ CO (S) (2),

wherein to the surface of the catalytic adsorber s denotes TIALLY ^¬ dene molecules.

5. The method according to claim 4, characterized in that the reaction weight at low temperatures and high surface concentrations of NH _{3 leads} to the formation of urea according to equation (2), but at high temperatures or low surface concentrations of NH ₃ from equation (1). is determined and leads to the release of CO ₂ .

6. The method according to claim 4, characterized in that the absorbent is set back in the CO ₂ release using water vapor in the original state according to

(NH ₂ ) ₂ CO → NH ₃ (S) + HNCO (s) (2a)

HNCO (s) + H ₂ O → NH ₃ (s) + CO ₂ (3)

7. The method according to any one of the preceding claims, characterized in that for the separation of water vapor and CO ₂ by condensation, a combined pressure and temperature control is used.

8. The method according to any one of the preceding claims, characterized in that alternative reaction mechanisms for

Binding of CO ₂ can be used, the z. B. for the formation of ammonium carbonate (NH ₂ CO ₂ -NH ₄ ⁺ ) accordingly 2 NH ₃ (S) + CO ₂ → NH ₂ CO ₂ ^" NH 4 ⁺ (s) (4!

to lead .

9. The method according to claim 8, characterized gekennzerchnet that the ammonium carbonate by hydrolysis in wassπger solution and / or a suitable catalytic surface at low temperatures to ammonium carbonate accordingly

NH ₂ CO ₂ ^~ NH ₄ ⁺ (s) + H ₂ O → (NH ₄ ) ₂ CO ₃ (5)

is implemented.

10. The method according to claim 9, characterized in that the ammonium carbonate thermally with elimination of water in

NH ₃ and CO ₂ accordingly

(NH ₄ ) ₂ CO ₃ → 2 NH ₃ (S) + CO ₂ + H ₂ O (6)

is decomposed.

11. The method according to any one of the preceding claims, characterized in that for Stromungstechnischen Realisie ^¬ tion two parallel-connected reactors are used, which are alternately charged to adsorb the CO ₂ with exhaust gas, and then, when the adsorber is largely loaded, from the exhaust stream are taken and for regeneration with Desorbergasgemisch, which is at the required temperature is charged.

12. The method according to any one of the preceding claims, characterized in that each one adsorption reactor and a regeneration reactor, which are connected in parallel, are used, wherein the catalyst required for the Reaktionsfuhrung continuously through a gas lock from the adsorption in the desorption and can be recycled ,

13. The method according to claim 12, characterized in that a rotatable disc stack is used as the catalyst, which is arranged so that the catalytic surfaces alternately through the adsorption and the desorption.

14. The method according to claim 12, characterized in that the catalyst is present as a debris of small particles large surface, which is fed to the adsorption at the gas outlet continuously, loaded on the way through the adsorption ^¬ reactor with CO ₂ , and the adsorption reactor at the gas inlet via a Gas lock again removed and the regeneration is supplied by desorption of CO ₂ .

15. The method according to any one of the preceding claims, characterized in that the Adsorptionskapazitat the catalytic material for CO _{2 is maintained} by a further, additional regeneration process, is stored in the Am ^¬ ammonia on the catalytic surface.

16. The method according to claim 15, characterized in that the Adsorptionskapazitat the catalytic material for CO2 is monitored by a sensor.

17. The method according to claim 15, characterized in that the loading of the catalyst with absorbent takes place in a separate process step following a CO 2 desorption, wherein by a suitable valve control first the Spulgaszufuhr stopped, then the supply of absorption medium started at Reaching the loading limit stopped again and then the reactor is completely separated by closing the outlet-side valves from the gas circuit, wherein the reaching of the load limit is detected by an output side gas sensor for the absorbent.

18. The method according to claim 17, characterized in that the further temporal concentration course of the absorption is detected by sensor means in the gas phase and used to Beurtei ^¬ development of the integrity of the catalytic adsorber.

19. Apparatus for carrying out the method according to claim 1 or one of claims 2 to 18, with reactors for the choice ^¬ use as adsorber or desorber of CO2, characterized by

at least one first reactor (10, 20, 30) for the catalytic adsorption of CO ₂ in an adsorber and

at least one second reactor (10 ', 20', 30 ') for the desorption of the CO ₂ from the adsorber by means of a Desorptionsgasge- mix, and

Desorbent-removing means, wherein the adsorber is an absorbent-adsorbed catalytic adsorber having high selectivity for the CO ₂ adsorption reaction (11, 21, 31),

and by control means for controlling the catalytic adsorption of CO ₂ from a CO ₂ -containing waste gas in the at least first reactor (10, 20, 30) and for controlling the desorption of the CO ₂ from the catalytic adsorber in the at least second reactor ( 10 ', 20', 30 ').

20. The apparatus according to claim 22, characterized in that means for controlling the gas flows are present, with which the reactors (10, 10 ') are each operated in alternating operation between adsorption and desorption. (FIGURE 1)

21. The device according to claim 20, characterized in that means for supplying an absorbent from a Vorratsbehalter (4) are present.

22. Device according to one of the preceding claims, characterized in that two parallel arranged reactors (20, 20 ') are present, which via a gas-tight

Lock (25) and via catalyst plates (15) are interconnected. (FIGURE 2)

23. The device according to claim 22, characterized in that the catalyst plates (15) have a circular base πss and are rotatable about an axis perpendicular to the gas flow axis (I).

24. Device according to claim 23, characterized by a catalyst (31) designed as a bed of catalytic particles, means for the continuous supply of the adsorbent-laden catalyst to at least one reactor (30, 30 '), gas-tight means (32, 32 ') for kontinuier ^¬ handy extraction of the laden with CO ₂ catalyst from at least a first reactor (30) and for feeding it to at least one second reactor (30'). (FIGURE 3)

25. The apparatus according to claim 19, characterized in that in the adsorption reactor (40) at least one temperature sensor (42) in the outlet region of the reactor and two CÜ ₂ -Konzen- trationssensoren (43, 44), one of which in the Emlassbereich and another in the outlet is arranged exist.

26. The device according to claim 19, characterized in that in the desorption reactor (50) at least one gas sensor for the concentration of the absorbent and a temperature sensor (42) are present whose signals for controlling the

Adsorptionskapazitat be used by loading with absorbent.

27. The device according to claim 26, characterized in that valves (V12, V13) are gas mixture and for discharging the laden with CO2 desorbate so ^¬ such as a valve (V14) for the controlled supply of absorbent present to control the supply of Desorber- that be controlled in dependence on the sensor signals.

28. Device according to one of the preceding claims, characterized in that an oxidic catalyst is used as adsorber.

29. The device according to claim 28, characterized in that the catalyst of TiO ₂ or a mixture of TiO ₂ and another metal oxide, in particular doped with V ₂ O ₅ , consists.

30. The device according to claim 28, characterized in that the catalyst consists of an ion-exchanged zeolite.